Method for synthesizing methyl ketone by using alkynediol byproduct

Abstract

The invention belongs to the technical field of fine chemical synthesis, and discloses a method for synthesizing methyl ketone by using an alkynediol byproduct. The method comprises the following steps: mixing the alkynediol byproduct polyketone polymer with a catalyst; introducing the mixed solution from the middle part of a tubular reactor, introducing N2 from the bottom of a tower reactor, entering the tubular reactor, and carrying out cracking reaction on the mixed solution in a bubbling manner to prepare methyl ketone; the catalyst is a solid acid catalyst and / or a solid base catalyst. According to the method, methyl ketone is prepared from the byproduct polyketone polymer of the alkyne diol, so that waste is turned into wealth, the raw material of the alkyne diol is synthesized again, and material waste is avoided; and the preparation process is simple, the reaction temperature is easy to control, the required equipment is simple, the production process is safe and reliable, and industrial production is easy. When the method is used for synthesizing methyl ketone, the polymer conversion rate is as high as 97.4%, and the methyl ketone yield is as high as 91.9%.

Description

Technical Field

[0001] The present invention belongs to the technical field of fine chemical synthesis, and particularly relates to a method for synthesizing methyl ketone by using by-products of alkynediol. Background Art

[0002] Currently, the production of alkynediol generally uses the improved Reppe, slurry bed or suspension bed process to carry out the reaction under normal pressure or low pressure conditions. In the reaction, acetylene and methyl ketone are used as raw materials, and methyl tert-butyl ether is used as a solvent. Since the Reppe reaction occurs under the catalysis of a large amount of KOH, the resulting alkynediol material is very viscous. This leads to the easy occurrence of side reactions during the reaction, that is, the aldol condensation reaction of methyl ketone under alkaline conditions, resulting in polyketone polymers such as dimers and polymers of methyl ketone. Due to the characteristics of the Reppe reaction, its side reactions are difficult to avoid, and the resulting polyketone polymers are basically treated as waste. This not only causes a large loss of raw materials and increases the production cost of alkynediol, but also brings great difficulties to the subsequent waste treatment and is not conducive to environmental protection. Therefore, providing an effective treatment method is of great significance for both the production of alkynediol and environmental protection. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. For this purpose, the present invention proposes a method for synthesizing methyl ketone by using by-products of alkynediol. The present invention uses the polyketone polymer, a by-product of alkynediol, to prepare methyl ketone, which can not only turn waste into treasure and resynthesize the raw materials of alkynediol to avoid material waste, but also has a simple preparation process and is easy for industrial production.

[0004] The formation of the polyketone polymer, a by-product of alkynediol, is mainly due to the aldol condensation reaction of methyl ketone under alkaline conditions. This reaction is a reversible reaction and can be converted into the raw material ketone under certain conditions. In order to reduce the production cost of alkynediol products and effectively treat the resulting polyketone polymers, the present invention proposes a method for synthesizing methyl ketone by using by-products of alkynediol, which catalyzes the polyketone polymer produced in the alkynediol reaction to regenerate the raw material methyl ketone.

[0005] The present invention provides a method for synthesizing methyl ketone by using by-products of alkynediol.

[0006] Specifically, a method for synthesizing methyl ketone by using by-products of alkynediol includes the following steps:

[0007] Mix the alkynediol by-product polyketone polymer with a catalyst to obtain a mixed solution; introduce the mixed solution into the middle of a shell-and-tube reactor, and introduce N2 into the bottom of a tower reactor. Enter the shell-and-tube reactor to cause the mixed solution to undergo a cracking reaction in a bubbling manner. The methyl ketone generated after the reaction is carried out of the upper end of the shell-and-tube reactor by N2; the catalyst is a solid acid catalyst and / or a solid base catalyst.

[0008] Preferably, the solid acid catalyst is SO4 2- / ZrO2 - SiO2.

[0009] Preferably, the solid base catalyst is OH - / ZrO2 - SiO2.

[0010] Preferably, the alkynediol by-product polyketone polymer is selected from at least one of methyl isobutyl ketone polymer, methyl isopentyl ketone polymer, acetone polymer, and methyl isopropyl polymer.

[0011] Preferably, the mass of the catalyst is 0.5% - 5% of the mass of the alkynediol by-product polyketone polymer. Further preferably, the mass of the catalyst is 2% - 5% of the mass of the alkynediol by-product polyketone polymer.

[0012] Preferably, the speed of introducing the mixed solution into the middle of the shell-and-tube reactor is 0.5 - 8 L / min; further preferably, the speed of introducing the mixed solution into the middle of the shell-and-tube reactor is 1 - 5 L / min.

[0013] Preferably, the liquid level is maintained at 30% - 80% after the mixed solution is introduced into the shell-and-tube reactor; further preferably, the liquid level is maintained at 40% - 60% after the mixed solution is introduced into the shell-and-tube reactor.

[0014] Preferably, the space velocity when N2 is introduced is 10 - 150 h -1 ; further preferably, the space velocity when N2 is introduced is 20 - 100 h -1 .

[0015] Preferably, the temperature of the cracking reaction is 150 - 210 °C; further preferably, the temperature of the cracking reaction is 160 - 190 °C.

[0016] Preferably, the pressure of the cracking reaction is 0.1 - 0.6 Mpa; further preferably, the pressure of the cracking reaction is 0.2 - 0.5 Mpa.

[0017] More specifically, a method for synthesizing methyl ketone using an alkynediol by-product includes the following steps:

[0018] Mix the alkynediol by-product polyketone polymer and the catalyst at a mass ratio of 1:0.5%-5% to obtain a mixed solution; feed the mixed solution into the middle of a tubular reactor at a flow rate of 0.5-8 L / min and maintain the liquid level at 30%-80%; after purging with N2, feed N2 into the bottom of a tower reactor at an hourly space velocity of 10-150 h -1 to enter the tubular reactor, and make the mixed solution undergo a cracking reaction in a bubbling manner. Control the temperature of the cracking reaction to be 150-210°C and the pressure to be 0.1-0.6 Mpa; the methyl ketone generated after the reaction is carried out of the upper end of the tubular reactor by N2.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] (1) The method for synthesizing methyl ketone using the alkynediol by-product provided by the present invention uses the polyketone polymer, which is a by-product of the Reppe reaction for synthesizing alkynediol, as a reaction raw material. Under the catalytic action, it decomposes into the raw material methyl ketone for synthesizing alkynediol by the Reppe reaction. By selecting the catalyst and optimizing the reaction process, the present invention can resynthesize the raw material methyl ketone of alkynediol, achieve the maximum atomic utilization rate of the raw materials, and reduce the production cost of alkynediol. Using this method to synthesize methyl ketone, the polymer conversion rate is as high as 97.4%, and the methyl ketone yield is as high as 91.9%.

[0021] (2) The present invention uses the polyketone polymer, which is a by-product of alkynediol, to prepare methyl ketone. It can not only turn waste into treasure, resynthesize the raw material of alkynediol, and avoid material waste; but also its preparation process is simple, the reaction temperature is easy to control, the required equipment is simple, the production process is safe and reliable, and it is easy to industrialize production. Specific Embodiments

[0022] In order to make those skilled in the art more clearly understand the technical solutions described in the present invention, the following examples are listed for illustration. It should be noted that the following examples do not limit the scope of protection required by the present invention.

[0023] The raw materials, reagents or devices used in the following examples can be obtained from conventional commercial channels or can be obtained by existing known methods without special instructions.

[0024] Examples 1-4

[0025] Examples 1-4 provide a method for synthesizing methyl ketone using the alkynediol by-product, including the following steps:

[0026] Mix each catalyst with the by-product methyl isobutyl ketone polymer of acetylenic diol in a mass ratio of 3%:1 evenly, and then transfer it to a tubular reactor. The liquid level of the mixed solution in the reactor is maintained within the range of 50%. The mixed liquid is introduced into the middle of the tubular reactor at a rate of 3 L / min, and then the air in the reactor is replaced with N2. N2 is introduced from the bottom of the tower reactor and passes through the tubular reactor in a bubbling manner to crack the mixed liquid in the tubular reactor. The pressure is controlled at 0.2 Mpa, and the booster pump is adjusted to maintain the N2 space velocity at 100 h -1 , and the temperature of the tubular reactor is maintained at 180 °C. As N2 gas is introduced at the bottom, the product methyl ketone at the upper end of the tubular reactor is carried out. The obtained methyl ketone is detected by liquid chromatography, and the conversion rate of the by-product methyl isobutyl ketone polymer of acetylenic diol and the yield of methyl ketone are calculated. The selection of catalysts and the test results in each example are shown in Table 1.

[0027] Table 1

[0028]

[0029] Examples 1-4 compared the effects of different catalysts on the polymer conversion rate and the yield of methyl ketone. As can be seen from Table 1, when the solid acid catalyst (SO4 2- / ZrO2-SiO2) and the solid base catalyst (OH - / ZrO2-SiO2) are selected, when the by-product methyl isobutyl ketone polymer of acetylenic diol is catalytically decomposed, the polymer conversion rate and the yield of methyl ketone are higher, and the effect is better.

[0030] Examples 2, 5-7

[0031] Examples 2, 5-7 provide a method for synthesizing methyl ketone using the by-product of acetylenic diol, including the following steps:

[0032] Respectively mix the solid acid catalyst (SO4 2- / ZrO2-SiO2) with different types of by-products of acetylenic diol (methyl isobutyl ketone polymer, methyl isopentyl ketone polymer, acetone polymer, methyl isopropyl ketone polymer) in a mass ratio of 3%:1 evenly, transfer it to a tubular reactor. The liquid level of the mixed solution in the reactor is maintained within the range of 50%. The mixed liquid is introduced into the middle of the tubular reactor at a rate of 3 L / min, and then the air in the reactor is replaced with N2. N2 is introduced from the bottom of the tower reactor and passes through the tubular reactor in a bubbling manner to crack the mixed liquid in the tubular reactor. The pressure is controlled at 0.2 Mpa, and the booster pump is adjusted to maintain the N2 space velocity at 100 h -1。The temperature of the tubular reactor was maintained at 180 °C. As N2 gas was introduced at the bottom to carry out the product methyl ketone at the upper end of the tubular reactor, the obtained methyl ketone was detected by liquid chromatography, and the conversion rate of the alkynediol by-product methyl isobutyl ketone polymer and the yield of methyl ketone were calculated. The selection of raw material types and test results in each example are shown in Table 2.

[0033] Table 2

[0034] Example Raw material type Polymer conversion rate / % Methyl ketone yield / % 2 Methyl isobutyl ketone polymer 97.3 88.7 5 Methyl isopentyl ketone polymer 85.7 79.1 6 Acetone polymer 77.3 68.2 7 Methyl isopropyl polymer 73.1 70.3

[0035] Examples 2, 5 - 7 studied the effects of different alkynediol by-products on the polymer conversion rate and the yield of methyl ketone. As can be seen from Table 2, when using methyl isobutyl ketone polymer and methyl isopentyl ketone polymer as raw materials, the solid acid catalyst has a better catalytic decomposition effect on the polymer in the alkynediol reaction, and the polymer conversion rate and the yield of methyl ketone are higher. Therefore, choosing methyl isobutyl ketone polymer as the raw material has the best effect.

[0036] Examples 2, 8 - 10

[0037] Examples 2, 8 - 10 provided a method for synthesizing methyl ketone using alkynediol by-products, including the following steps:

[0038] The solid acid catalyst (SO4 2- / ZrO2 - SiO2) was respectively mixed evenly with methyl isobutyl ketone polymer at a mass ratio of 1%:1, 2%:1, 3%:1, 4%:1, transferred to a tubular reactor. The mixed solution was maintained at a liquid level range of 50% in the reactor, and the mixed liquid was introduced into the middle of the tubular reactor at 3 L / min. Then, the air in the reactor was replaced with N2. N2 was introduced from the bottom of the tower reactor and bubbled through the tubular reactor to crack the mixed liquid in the tubular reactor. The pressure was controlled at 0.2 Mpa, and the booster pump was adjusted to maintain the N2 space velocity at 100 h -1 。The temperature of the tubular reactor was maintained at 180 °C. As N2 gas was introduced at the bottom to carry out the product methyl ketone at the upper end of the tubular reactor, the obtained methyl ketone was detected by liquid chromatography, and the conversion rate of the alkynediol by-product methyl isobutyl ketone polymer and the yield of methyl ketone were calculated. The catalyst - to - raw material feeding ratio and test results in each example are shown in Table 3.

[0039] Table 3

[0040]

[0041] Examples 2, 8 - 10 studied the effects of different catalyst - to - raw material feeding ratios on the polymer conversion rate and the yield of methyl ketone. As can be seen from Table 3, when the feeding ratio of the catalyst is 3%, the polymer conversion rate and the yield of methyl ketone are the highest, and the effect is the best.

[0042] Examples 2, 11 - 14

[0043] Examples 2, 11 - 14 provide a method for synthesizing methyl ketone using alkynediol by - products, including the following steps:

[0044] Mix the solid acid catalyst (SO4 2- / ZrO2 - SiO2) with the methyl isobutyl ketone polymer in a mass ratio of 3%:1 evenly, transfer it to a tubular reactor, and control the holding liquid levels of the mixed solution in the reactor in each example to be 30%, 40%, 50%, 60%, 70% and 80% respectively. The mixed liquid is introduced into the middle of the tubular reactor at a rate of 3 L / min, and then the air in the reactor is replaced with N2. N2 is introduced from the bottom of the tower reactor and passes through the tubular reactor in a bubbling manner to crack the mixed liquid in the tubular reactor. The pressure is controlled at 0.2 Mpa, and the booster pump is adjusted to maintain the N2 space velocity at 100 h -1 . The temperature of the tubular reactor is maintained at 180 °C. As N2 gas is introduced at the bottom, the methyl ketone product at the upper end of the tubular reactor is taken out, and the obtained methyl ketone is detected by liquid chromatography, and the conversion rate of the alkynediol by - product methyl isobutyl ketone polymer and the yield of methyl ketone are calculated. The liquid levels and test results in each example are shown in Table 4.

[0045] Table 4

[0046] Example Liquid level / % Polymer conversion rate / % Methyl ketone yield / % 11 30 84.2 73.3 12 40 84.9 77.7 2 50 97.3 88.7 13 60 88.9 79.3 14 70 79.3 69.2

[0047] Examples 2, 11 - 14 studied the effects of different liquid levels on the polymer conversion rate and the yield of methyl ketone. As can be seen from Table 4, when the liquid level is 50%, the polymer conversion rate and the yield of methyl ketone are the highest, and the effect is the best.

[0048] Examples 2, 15 - 18

[0049] Examples 2, 15 - 18 provide a method for synthesizing methyl ketone using alkynediol by - products, including the following steps: Mix the solid acid catalyst (SO4 2- / ZrO2 - SiO2) with the methyl isobutyl ketone polymer in a mass ratio of 3%:1 evenly, transfer it to a tubular reactor, the holding liquid level range of the mixed solution in the reactor is 50%, the mixed liquid is introduced into the middle of the tubular reactor at a rate of 3 L / min, and then the air in the reactor is replaced with N2. N2 is introduced from the bottom of the tower reactor and passes through the tubular reactor in a bubbling manner to crack the mixed liquid in the tubular reactor. The pressures in each example are controlled at 0.1, 0.2, 0.3, 0.4 and 0.5 Mpa respectively, and the booster pump is adjusted to maintain the N2 space velocity at 100 h -1The temperature of the tubular reactor is maintained at 180 °C. As N2 gas is introduced at the bottom to carry out the product methyl ketone at the upper end of the tubular reactor, the obtained methyl ketone is detected by liquid chromatography, and the conversion rate of the by-product methyl isobutyl ketone polymer of the acetylenic diol and the yield of methyl ketone are calculated. The pressures and test results in each example are shown in Table 5.

[0050] Table 5

[0051]

[0052]

[0053] Examples 2, 15 - 18 studied the effects of different pressures on the polymer conversion rate and the yield of methyl ketone. As can be seen from Table 5, when the reaction pressure is 0.3 MPa, the polymer conversion rate and the yield of methyl ketone are the highest, and the effect is the best.

[0054] Examples 16, 19 - 22

[0055] Examples 16, 19 - 22 provided a method for synthesizing methyl ketone using the by-product of acetylenic diol, including the following steps: mixing the solid acid catalyst (SO4 2- / ZrO2 - SiO2) with the methyl isobutyl ketone polymer in a mass ratio of 3%:1 evenly, transferring it to the tubular reactor, the liquid level range of the mixed solution in the reactor is maintained at 50%, and in each example, the mixed liquid is introduced into the middle of the tubular reactor at 1, 2, 3, 4, and 5 L / min respectively, then the air in the reactor is replaced with N2, and N2 is introduced from the bottom of the tower reactor and passes through the tubular reactor in a bubbling manner to crack the mixed liquid in the tubular reactor, the pressure is controlled at 0.3 Mpa, and the booster pump is adjusted to keep the N2 space velocity at 100 h -1 。The temperature of the tubular reactor is maintained at 180 °C. As N2 gas is introduced at the bottom to carry out the product methyl ketone at the upper end of the tubular reactor, the obtained methyl ketone is detected by liquid chromatography, and the conversion rate of the by-product methyl isobutyl ketone polymer of the acetylenic diol and the yield of methyl ketone are calculated. The flow rates and test results in each example are shown in Table 6.

[0056] Table 6

[0057]

[0058]

[0059] Examples 16, 19 - 22 studied the effects of different flow rates on the polymer conversion rate and the yield of methyl ketone. As can be seen from Table 6, when the feed flow rate is 3 L / min, the polymer conversion rate and the yield of methyl ketone are the highest, and the effect is the best.

[0060] Examples 16, 23 - 27

[0061] Examples 16, 23 - 27 provide a method for synthesizing methyl ketone using alkynediol by - products, including the following steps: Mix a solid acid catalyst (SO4 2- / ZrO2 - SiO2) with a methyl isobutyl ketone polymer in a mass ratio of 3%:1 evenly, transfer it to a tubular reactor. The mixed solution maintains a liquid level range of 50% in the reactor. The mixed liquid is introduced into the middle of the tubular reactor at a rate of 3 L / min. Then, displace the air in the reactor with N2. Introduce N2 from the bottom of the tower reactor, and make the mixed liquid crack in the tubular reactor in a bubbling manner through the tubular reactor. Control the pressure at 0.3 Mpa, adjust the booster pump, so that the N2 space velocities in each example are maintained at 20, 50, 80, 100, 120, and 150 h -1 . Maintain the temperature of the tubular reactor at 180 °C. As N2 gas is introduced at the bottom, the methyl ketone product at the upper end of the tubular reactor is carried out. Detect the obtained methyl ketone by liquid chromatography, and calculate the conversion rate of the alkynediol by - product methyl isobutyl ketone polymer and the yield of methyl ketone. The space velocity, raw material feeding ratio, and test results in each example are shown in Table 7.

[0062] Table 7

[0063]

[0064]

[0065] Examples 16, 23 - 27 studied the effects of different space velocities on the polymer conversion rate and the yield of methyl ketone. As can be seen from Table 7, when the space velocity is 100 h -1 , the polymer conversion rate and the yield of methyl ketone are the highest, and the effect is the best.

[0066] Examples 16, 28 - 31

[0067] Examples 16, 28 - 31 provide a method for synthesizing methyl ketone using alkynediol by - products, including the following steps: Mix a solid acid catalyst (SO4 2- / ZrO2 - SiO2) with a methyl isobutyl ketone polymer evenly in a mass ratio of 3%. Transfer it to a tubular reactor. The mixed solution maintains a liquid level range of 50% in the reactor. The mixed liquid is introduced into the middle of the tubular reactor at a rate of 3 L / min. Then, displace the air in the reactor with N2. Introduce N2 from the bottom of the tower reactor, and make the mixed liquid crack in the tubular reactor in a bubbling manner through the tubular reactor. Control the pressure at 0.3 Mpa, adjust the booster pump, so that the N2 space velocity is maintained at 100 h -1。In each embodiment, the temperature of the shell-and-tube reactor was maintained at 150, 165, 180, 195, and 210 °C respectively. As N2 gas was introduced at the bottom to carry out the product methyl ketone at the upper end of the shell-and-tube reactor, the obtained methyl ketone was detected by liquid chromatography, and the conversion rate of the by-product methyl isobutyl ketone polymer of alkynediol and the yield of methyl ketone were calculated. The reaction temperatures and test results in each embodiment are shown in Table 8.

[0068] Table 8

[0069]

[0070] Examples 16, 28 - 31 studied the effects of different reaction temperatures on the polymer conversion rate and the yield of methyl ketone. As can be seen from Table 8, when the reaction temperature was 180 °C, the polymer conversion rate and the yield of methyl ketone were the highest, and the effect was the best.

[0071] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

Claims

1. A method for synthesizing methyl ketone using acetylenediol byproducts, characterized in that: The following steps are involved: The polyketone polymer produced as a byproduct of acetylene glycol is mixed with a catalyst to obtain a mixed solution; the mixed solution is introduced from the middle of a tubular reactor, and N2 is introduced from the bottom of a tower reactor into the tubular reactor to cause the mixed solution to undergo a cracking reaction by bubbling, and the methyl ketone generated after the reaction is taken out from the upper end of the tubular reactor by N2; the catalyst is a solid acid catalyst and / or a solid base catalyst.

2. The method according to claim 1, characterized in that: The solid acid catalyst is SO4 2- / ZrO2-SiO2.

3. The method according to claim 1, characterized in that: The solid base catalyst is OH - / ZrO2-SiO2.

4. The method according to any one of claims 1 to 3, characterized in that The acetylene glycol byproduct polyketone polymer is selected from at least one of methyl isobutyl ketone polymer, methyl isoamyl ketone polymer, acetone polymer and methyl isopropyl polymer.

5. The method according to claim 2 or 3, characterized in that: The mass of the catalyst is 0.5% to 5% of the mass of the acetylene glycol byproduct polyketone polymer.

6. The method according to any one of claims 1 to 3, characterized in that The mixed liquid is introduced into the middle of the tubular reactor at a speed of 0.5-8 L / min.

7. The method according to claim 6, characterized in that After the mixed liquid is introduced into the tubular reactor, the liquid level is maintained at 30%-80%.

8. The method according to any one of claims 1 to 3, characterized in that The space velocity when N2 is introduced is 10-150h -1 Preferably, the space velocity when N2 is introduced is 20-100h -1 .

9. The method according to any one of claims 1 to 3, characterized in that: The temperature of the cracking reaction is 150-210° C.; the pressure of the cracking reaction is 0.1-0.6 MPa.

10. The method according to claim 9, characterized in that The temperature of the cracking reaction is 160-190° C.; the pressure of the cracking reaction is 0.2-0.5 MPa.

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